Influence of fish consumption on the distribution of serum cholesterol in lipoprotein fractions: comparative study among fish-consuming and non-fish-consuming populations

The objective of this study was to investigate serum lipoprotein levels in order to assess cardiovascular disease (CVD) risk factors between fish-consuming populations and non-fish-consuming populations, as it has been speculated that fish intake reduces CVD risk. A representative sample of one thousand subjects (529 men and 471 women) were selected, with ages ranging from 20 to 70 years, from 40 villages belonging to fish-consuming (500) or non-fish-consuming (500) populations. Serum lipoprotein lipids such as total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were analysed biochemically using standard procedures. The ratios of TC: HDL-C and LDL-C: HDL-C were computed. Mean values of serum LDL-C and the ratios of LDL-C : HDL-C and TC : HDL-C were significantly lower and HDL-C levels were higher in fish-consumers than in non-fish-consumers, The concentrations of HDL-C decreased with increasing age, while the reverse was true for LDL-C and for the LDL-C : HDL-C and TC : HDL-C ratios. There were significant sex differences for certain age groups in both of the population groups. The 5th, 50th and 95th percentile cut-off values for these parameters were lower in fish-consumers than in non-fish-consumers. The prevalence of individuals at risk of CVD because of low HDL-C (<35 mg/dL), high LDL-C (>130 mg/dL) and their atherogenic ratios (LDL-C : HDL-C > 3.5 and TC : HDL-C > 4.5) was significantly greater in non-fish-consumers. This study highlights that the fish-consuming population had a lower atherogenic risk than the non-fish-consuming population. The intake of fish may have substantial implications for public health and health economy by decreasing the risk of CVD. However, more studies are warranted to better define the mechanisms of cardioprotection by dietary fish and fish oils.